Assembly of Interlocked Superstructures with a Titanium Oxide Molecular Ring in Water

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Inorganic Chemistry

Background:

• Mechanical interlocked molecular architectures (MIMAs) are typically constructed using organic components.
• Crown ethers are well-established macrocyclic receptors for cations, crucial in organic supramolecular chemistry.
• Developing inorganic analogues for MIMAs can expand the scope and properties of these complex structures.

Purpose of the Study:

• To synthesize and characterize novel [2]catenane, [2]rotaxane, and [2]pseudorotaxane architectures.
• To investigate the use of a cyclic titanium oxide cluster as a core component for MIMAs.
• To evaluate the stability and potential applications of these inorganic-organic hybrid supramolecular assemblies in aqueous media.

Main Methods:

• Synthesis of catenane, rotaxane, and pseudorotaxane structures.
• Characterization using spectroscopic techniques (e.g., NMR, IR).
• Assessment of structural integrity and stability in aqueous solutions, including acidic conditions.

Main Results:

• Successful synthesis of [2]catenane, [2]rotaxane, and [2]pseudorotaxane using a cyclic titanium oxide cluster ([Ti₈O₈(SO₄)₁₆]^16-).
• The synthesized molecules remained intact after synthesis and upon redissolution in acidic water.
• Demonstrated stability in aqueous environments, highlighting the robustness of the titanium oxide cluster.

Conclusions:

• The cyclic titanium oxide cluster serves as a viable inorganic analogue to crown ethers for constructing MIMAs.
• These novel inorganic-organic hybrid assemblies exhibit significant stability in water.
• The findings open avenues for designing advanced supramolecular materials with potential applications in catalysis, sensing, and nanotechnology.